No-Bake Biscuit Cake

In a bowl, whisk together the egg, sugar, salt, flour, and starch until smooth.

Pour in the milk and whisk thoroughly until combined.

Transfer the mixture to a saucepan and cook over medium heat, stirring constantly, until the custard thickens (about 5–7 minutes).

Remove from heat, add the butter, and stir until completely melted. Let it cool for 5 minutes.

In a baking dish, arrange a layer of biscuits, then top with ⅓ of the custard and spread evenly. Repeat the layers: biscuits → ½ of the remaining custard → biscuits → remaining custard.

Cover with plastic wrap pressed directly onto the surface and refrigerate.

Melt the chocolate with the vegetable oil (in the microwave or using a double boiler) and stir until smooth.